Autobiographical Memory: What Is It?

In psychology, there is much debate to whether this terminology is relevant anymore. For example, the Oxford Dictionary of Psychology merely describes autobiographical memory as another name for episodic memory. Indeed, it is seen that there is significant similarities between autobiographical memory and episodic memory (as well as other types of memory) and some textbooks disregard the terminology altogether. However, this situation could merely be the result of an over-simplification of the autobiographical memory function and a reductionist attitude. In this essay, the main features of autobiographical memory will be discussed, the similarities and differences between autobiographical memory and other types of memory will be explored and the main functions of autobiographical memory will be analysed.

In current understanding, autobiographical memory can be affected and sub-divided into four major dimensions. Firstly, the semantic knowledge of an experience that cannot be strictly remembered in episodic memory (such as the knowledge of being born in a particular hospital) or the noetic dimension (Tulving, 1972).

The secondary dimension (or distinction) is the reconstructed memory and the copied memory (Brewer, 1986). Copied memories are memories that are primarily autonoetic and are marked with excessive “irrelevant” detail and vividness whereas reconstructed memories can be affected by new experiences and noetic information. As such, these memories can be unconsciously reconstructed to achieve cohesiveness with the newer information.

The tertiary dimension is the difference between generic autobiographical memories and specific autobiographical memories (Neisser, 1986). Generic autobiographical memories are memories of repeated, mundane events – often earmarked for their possible involvement in déjà vu whereas specific autobiographical memories hone in on specific, novel events. These specific memories can also be linked to the phenomenon that is flashbulb memories.

The fourth dimension in autobiographical memory is the perspective in which the memory is seen. Nigro and Neisser (1983) found that there were two significant types of memory perspective: the observer viewpoint (i.e. from an outside viewpoint, not the person’s own) and the field viewpoint (the viewpoint of the individual whose memory it is). These two differences can be used to highlight the difference between copied memories and reconstructed memories as well as show how autobiographical memories alter with time. Older memories were more likely to be reconstructed than newer memories (Nigro and Nesser, 1983; Robinson and Swanson, 1993).

Perhaps the greatest contrast between autobiographical memories is that of procedural memory. Procedural memory - unlike semantic, episodic and autobiographical memory – is an implicit memory type whereas semantic, episodic and autobiographical memories are explicit memory. For example, to know how to ride a bike is procedural memory and remembering riding a bike is autobiographical. To fully display this, the case of HM is ideal (Scoville and Milner, 1957).

HM was an epilepsy patient who has some preventative psychosurgery, removing most of his hippocampus, parahippocampal gyrus, and amygdala. This surgery caused a great difficulty in creating explicit long term memories. However, his procedural memory was intact as his scores in mirror star-drawing tests proved. The tests required HM to draw stars whilst observing his movements in a mirror. Despite not remembering ever doing the test, his scores improved as would be expected from someone who did not have significant brain damage. Neurologically speaking, procedural memories are considered to be more related to the cerebellum and basal ganglia and are related to the Marr/Albus theory of learning motor skills as well as the motor cortex and somatosensory cortex. The other two major types of memory that autobiographical memory is associated with is semantic memory and episodic memory.

Semantic memory is the type of memory that is concerned with meaning retention and abstract memories that do not need to have a specific association with the individual’s temporal-spatial existence (i.e. knowing that the capital of France is Paris.) There is the possibility of autobiographical and semantic overlap as described above. These semantic-autobiographic memories can be shown as thus: remembering the fact that you were born in a particular hospital or remembering an episode where you are being told that you were born in a particular hospital.

There are two main differences in which semantic memory and autobiographical memory works. Firstly, is the neurological area(s) associated with semantic and autobiographical memories. The exact neurological location of the semantic memory is still up for debate but it is relatively clear that there is at least some degree of separation. The first area where it is considered that semantic memory resides is in the parahippocampal cortices. Vargha-Khadem et al. (1997) discovered that patients who had hippocampal damage or removal but the parahippocampal cortices remained still had some semantic memory ability compared to total obliteration of episodic memory. Newer research indicates that semantic memory is more widespread than just within the medial temporal lobes. Oliver and Thompson-Schill (2003) discovered that there were some hemispheric differences with certain types of semantic memory as well as parietal lobe activation (color and form; motion and size respectively.)

Secondly is the way that semantic memories and autobiographical memories are encoded into memory. In both the Multi-Store Model of Memory and the Levels of Processing Model of Memory, there is the prevalence of repetitious and elaborative (and therefore, a more complicated) concerned with semantic memory (Craik and Lockhart, 1972; Atkinson and Shiffrin, 1968). With autobiographical memory, these active processes do not occur. Autobiographical memories – perhaps with the exception of flashbulb memories – are passive, automatically and recorded without any resulting rehearsal or elaboration.

However, these differences do not mean that they are separate or entirely different. Maguire et al (2009) discovered that there is an intrinsic link between semantic dementia and the capabilities of autobiographical memory. Maguire et al took the case study of a patient with semantic dementia – codenamed AM – and took functional MRI scans annually to monitor the autobiographical memory networks over the course of his disease. It was found that as time went on, the autobiographical memory network atrophied. This indicated that despite semantic dementia patients showing a better hold of autobiographical memory; there is a link between these two types of memory.

Episodic memory, on the other hand, is where most of the similarities between autobiographical memory and itself occur. Episodic memory, in general, is the term for memories that pertain to certain events in an individual’s timeline. Despite the surface similarity to autobiographical memories, there are differences.

A semantic differential is how episodic memories appear in lucidity - differing with autobiographical memory in the sense of “mental time travel” (Wheeler, Strauss and Tulving, 1997: p331). Episodic memory is the ultimate cognitive TARDIS in that retrospect; using seemingly insignificant details that are irrelevant to the purpose of returning to that memory – such as clothing, smells and mundane facts – bleed through this and you “relive” the memory. Autobiographical memory does not have this capability.

Autobiographical memory is – primarily - an imprint experience, a ghosting, sketchy version where the important facts remain and unnecessary detail is discarded. Autobiographical memory, as previously discussed, is more subject to hindsight biases in the attempt to maintain a homogenous continuity as well as perspective shifts and interference of noetic information. The temporal factor also becomes important here (Conway and Pleydell-Pearce, 2000). Episodic memory is ‘measured’ in relative time sequencing (seconds, minutes, hours) whereas autobiographical memory skims the temporal frame.

Neurologically speaking, there has been significant research within the location (or loci) of the episodic memory. Despite the obvious link between the hippocampal cortices and loss of episodic memory as shown with HM, the pre-frontal cortex has been shown to have significant involvement in retrieval (Tulving, Kapur, Craik, Moscovitch, and Houle, 1994). Indeed, this has been involved in the hemispheric encoding/retrieval asymmetry hypothesis (Habib, Nyberg, & Tulving, 2003) which hypotheses that the right hemisphere of the pre-frontal cortex is more involved with retrieval of episodic memory than semantic information or the left hemisphere. However, in a cross-analysis of autobiographical and episodic memory tests using a functional MRI scan; autobiographical tests activated the left ventromedial pre-frontal cortex which rarely occurred within episodic memory tests. Conversely, episodic tests found that the right mid-dorsolateral pre-frontal cortex was activated and yet this activation did not occur in autobiographical tests. (Gilboa, 2004).

One very significant overlap between episodic memory and autobiographical memory is flashbulb memories. Flashbulb memories are memories often typecast with particularly traumatic events in the global timeline such as the assassination of JFK or the World Trade Centre terrorist attack. These memories are vivid because the event was shocking to the individual that the memory is perfectly preserved (as opposed to repressed memories). There is this overlap because although the vividness of the memory and the transdimensional clarity of the memory indicate an episodic memory, these are also part of the autobiographical “copied” memory bank. Also, these memories can have an alteration of perspective that is expected over time but little other distortion primarily occurs.

Compared to other types memory, autobiographical memory has a stronger role in day to day life – particular in aspects of directive information, identity and social aspects.

The directive function is a form of learning through experience, using past conclusions and failures to guide future action and behaviour (Baddeley, 1987). This theory of learning has been shown with striking events and with “scripts” and “schemas” with childhood learning. Striking events, such as 11th September 2001, found that people changed their behaviours and routines in order to avoid another possible attack and shows the basic evolutionary basis of this learning type (Pillemer, 2003). Another example of this is the basic guidelines for childcare (Goldsmith and Pillemer, 1988). Goldsmith and Pillmer asked students to describe vivid memories of their childhood and with 46%, the memories came in the form of advice or basic instructions for childcare as opposed to specific events. This cannot occur within episodic memory. Episodic memory, as previously discussed, has the specific quality of mental time travel. Animals do not have this ability but can learn from experience (Suddendorf and Busby, 2003).

The formation of identity is linked with autobiographical memory as it dictates where the individual has came from, where they are and where they could be or should never be (Conway, 2005). This distinction is very important for the construction of the self, for the self-questioning of motivation and for the boundaries for realistic goals. This link is as such that Conway and Pleydell-Pearce (2000) combined aspects of autobiographical memory and the working self in a self-memory system which create and control a system of cues to moderate and activate certain workings of the inner self. This is particularly seen in dementia patients who seem to lose a sense of the self. This has been shown through the success of reminisce therapy which not only improves a sense of the self but has a better overall cognition rate (Woods, Spector, Jones, Orrell and Davies, 2005).

Finally, there is the social side of autobiographical memory. The importance of this function has been linked to the instinctual human adoration of a story. In this, autobiographical memory is a social tool for both those who were present and those who were not present at the remembered event. To explain an experience to an individual who was present at a certain event increases a feeling of bonding with that individual as well as having the effect of increasing the relationship. (Bluck, 2003). Similarly, when someone explains the experience to someone who was not present at an event is used to promote a more believable relationship; particularly found within parental and child relationships (Bluck, 2003).

In conclusion, it is difficult to truly separate where the autobiographical memory and other forms of explicit memories begin and end. In order to truly understand them, they are separate systems but are cohesively connected in a tangled web with different coloured twine – clearly different systems caught up together because they are similar. Despite this connectiveness, autobiographical memory has differing functions to other forms of memory and is located in different parts of the brain.

References:

Atkinson, R.C.; Shiffrin, R.M. (1968). Human memory: A proposed system and its control processes. In K. W. Spence & J.T.Spence. The Psychology of Learning and Motivation (Volume2; 89–195). New York: Academic Press.

Baddeley, A.D. (1987). But what the Hell is it for? In Gruneberg, M.M.; Morris, P.E. and Sykes, R. N. (Eds) Practical Aspects of Memory: Current Research and issues. (p-3-18) Chichester, : Wiley.